[Elecraft] ALC implementation

[Don Wilhelm]

Brian,

ALC should never be used for power control doing so usually causes RF 
compression and distortion.

Many of the digital application instructions tell you to set for NO ALC 
as a *maximum* audio level, set the power control for the maximum 
desired and then reduce the audio level to reduce the power - I think 
that is why the slider in WSJTX is labeled POWER when it is really an 
audio level control.

The above method works fine for many transceivers, but NOT for Elecraft 
which measures the actual power output, compares it with the set power 
and adjusts the RF drive accordingly.  This is a fully closed loop 
system.  As far as I know, Elecraft is the only amateur transceiver 
using that type of system.

With Elecraft transceivers (except for the K2), adjust the audio drive 
level to produce 4 bars solid on the ALC meter with the 5th bar flashing 
(this is the NO ALC point.  Then leave it that way and adjust the 
desired power with the power knob.  Doing otherwise will result in low 
power at the start and power hunting as the transmission goes on.

73,
Don W3FPR

On 6/28/2019 2:38 PM, Brian Denley wrote:
> I have always thought that ALC is not appropriate for power control.  It’s a protection system.  Over use of ALC acts like compression.  No?
>